1. Technical Field
The present invention relates to dump bodies on trucks. More particularly the present invention relates to dump bodies which are pivotally mounted such that the front may be elevated and the contents removed by gravity through a chute located in a rear tailgate. Specifically, the present invention relates to an improvement in coal chutes which enhances the longevity and operability by means of an easily replaceable coal chute door within an elastomeric track.
2. Background Information
Many trucks have a bed or body that is lifted upwardly relative to the vehicle to unload materials by gravity from within the bed. Dump bodies for industrial use, such as dump trucks and coal trucks, typically employ a tailgate which is pivotally mounted to the top of the side walls of the dump body and extends across the width of the bed, such that it may swing between an open and closed position as the front of the dump body varies in elevation.
These rear tailgates oftentimes include a center door assembly called a “coal chute”. The coal chute is substantially narrower than the rear tailgate and includes a door that can be selectively opened or closed. Common coal chute designs involve sliding the door up and down within tracks mounted in the sidewalls of the chute. Using a pivot arm, the user draws the door upwards along the chute door track before the bed of the dump truck is lifted. As the bed is lifted, the material within the bed exits through the coal chute in a contained and controlled stream that can be fed directly onto a ditch, intake basin, or onto a conveyor belt.
Due to the enormous tonnage carried by such trucks and the abuse to the walls of such truck bodies, the retaining chute door and the door track is subjected to distorting forces and are oftentimes broken or dented by movement of the material within the dump body or through the chute itself. When the cute door or track becomes distorted, the chute's effectiveness is diminished as the door cannot form a proper seal or slide within the track. Therefore gravel, coal, sand or other particulate matter can escape through the resulting gap. Consequently, it is not uncommon for the chute door to become unusable and require replacement or repair.
Replacing or repairing parts of the chute is very time consuming and expensive. Typical chutes have welded tracks, pivot arms, plates, and various other components. The chute assembly itself is welded onto the tailgate and difficult to remove. Furthermore, when the chute door or track is repaired or replaced, these items must be re-welded to the tailgate body, adding more time and expense to the process of replacing or repairing a part of the chute.
Therefore, the need exists for a center door assembly for a dump bed which includes easily replaceable and repairable parts, which parts are not welded to the tailgate so disassembly and reassembly time and expense will be minimized.